[dhcp] Add IANA-defined values for all current EFI client architectures

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/dhcp.h

diff --git a/src/include/ipxe/dhcp.h b/src/include/ipxe/dhcp.h
index b7a5f00..a1f9ee2 100644
--- a/src/include/ipxe/dhcp.h
+++ b/src/include/ipxe/dhcp.h
@@ -274,8 +274,9 @@
 
 /** DHCP client architecture values
  *
- * These are defined by the PXE specification and redefined by
- * RFC4578.
+ * These are originally defined by the PXE specification, redefined by
+ * RFC4578, redefined again by RFC5970, and now maintained in the IANA
+ * DHCPv6 parameters registry.
  */
 enum dhcp_client_architecture_values {
 	/** Intel x86 PC */
@@ -302,6 +303,24 @@
 	DHCP_CLIENT_ARCHITECTURE_ARM32 = 0x000a,
 	/** EFI 64-bit ARM */
 	DHCP_CLIENT_ARCHITECTURE_ARM64 = 0x000b,
+	/** EFI 32-bit RISC-V */
+	DHCP_CLIENT_ARCHITECTURE_RISCV32 = 0x0019,
+	/** EFI 64-bit RISC-V */
+	DHCP_CLIENT_ARCHITECTURE_RISCV64 = 0x001b,
+	/** EFI 128-bit RISC-V */
+	DHCP_CLIENT_ARCHITECTURE_RISCV128 = 0x001d,
+	/** EFI 32-bit MIPS */
+	DHCP_CLIENT_ARCHITECTURE_MIPS32 = 0x0021,
+	/** EFI 64-bit MIPS */
+	DHCP_CLIENT_ARCHITECTURE_MIPS64 = 0x0022,
+	/** EFI 32-bit Sunway */
+	DHCP_CLIENT_ARCHITECTURE_SUNWAY32 = 0x0023,
+	/** EFI 64-bit Sunway */
+	DHCP_CLIENT_ARCHITECTURE_SUNWAY64 = 0x0024,
+	/** EFI 32-bit LoongArch */
+	DHCP_CLIENT_ARCHITECTURE_LOONG32 = 0x0025,
+	/** EFI 64-bit LoongArch */
+	DHCP_CLIENT_ARCHITECTURE_LOONG64 = 0x0027,
 };
 
 /** Client network device interface */